Options Trading Basics: Calls, Puts, Premium & How They Work

What Is an Option?

An option is a derivative contract that gives the buyer a right — but not an obligation — to buy or sell an underlying asset (a stock or index) at a predetermined price (the "strike price") on or before a specific date (the "expiry"). In exchange for this right, the buyer pays a price called the "premium" to the seller (also called the "writer"). There are two basic types:

Buying vs Selling (Writing) Options

This is the distinction that matters most for understanding risk:

• Option buyers pay a premium upfront. Their maximum loss is limited to the premium paid — if the trade doesn't work out, the option simply expires worthless and the buyer loses the premium, nothing more.
• Option sellers (writers) receive the premium upfront but take on the obligation to fulfil the contract if the buyer exercises it. For uncovered (naked) option selling, potential losses can significantly exceed the premium received — for a naked call seller, losses are theoretically unlimited if the underlying price rises sharply, since there's no cap on how high a price can go.

What Determines an Option's Premium?

Premium is influenced by several factors, often summarised by "the Greeks" in more advanced material:

• Intrinsic value: the immediate exercise value, if any (e.g., for a call, how much the underlying price exceeds the strike price)
• Time value: reflects the time remaining until expiry — generally, more time means more premium, all else equal, because there's more opportunity for the underlying to move favourably
• Volatility: higher expected volatility in the underlying generally increases premium, since larger price swings increase the chance of the option finishing favourably for the buyer

Time value decays as expiry approaches — this is often referred to as "time decay" and works against option buyers (all else equal, an option becomes less valuable simply due to the passage of time) and in favour of option sellers.

Taxation and Turnover Implications

F&O trading, including options, is treated as non-speculative business income for tax purposes in India, with specific turnover calculation rules that can trigger tax audit requirements even for traders with relatively modest absolute profit or loss. This is covered in detail in our F&O taxation guide, which is essential reading before any active options participation, given the ITR-3 filing and potential audit obligations involved.

A Word on Suitability

Options can serve legitimate purposes — including hedging existing positions — in the hands of experienced participants who understand pricing dynamics and risk management. For most retail investors, particularly those building wealth through a long-term approach as described in our beginner's investing guide, options trading represents a fundamentally different activity from investing, with different risk characteristics, skill requirements, and a documented track record of net losses for the majority of individual participants.